Aviat Space Envir Md
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Aviat Space Envir Md · Dec 1992
Randomized Controlled Trial Comparative Study Clinical TrialLimited heat transfer between thermal compartments during rewarming in vasoconstricted patients.
Thermoregulatory vasoconstriction may serve to separate and limit heat transfer between peripheral and central thermal compartments, in effect providing a thermal buffer for central temperature. We hypothesized that thermoregulatory vasoconstriction would limit heat transfer to the central compartment in patients warmed cutaneously. Hypothermic patients (central temperatures < 35 degrees C) recovering from surgery were randomly assigned to receive forced-air warming (n = 6) or warmed cotton blankets (n = 6). ⋯ Despite a significantly greater increase in mean skin-surface temperature with forced-air warming, central temperature in the two groups did not significantly differ. All patients vasoconstricted and there was no difference in oxygen consumption between groups. These data confirm that thermoregulatory vasoconstriction limits heat transfer from peripheral to central thermal compartments and impedes skin surface warming of the body core.
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Aviat Space Envir Md · Dec 1992
Comparative StudyComparison of four noninvasive rewarming methods for mild hypothermia.
Four noninvasive rewarming techniques for mildly hypothermic subjects were compared. Seven subjects were cooled in a water bath of 15 degrees C for 2 h to an average esophageal temperature (Tes) of 36 degrees C. Thereafter, the subjects were rewarmed by immersion of the body in a water bath of 42 degrees C (Method 1), the body but not the extremities in water of 42 degrees C (Method 2), only the extremities in water of 42 degrees C (Method 3), or spontaneous rewarming in blankets (Method 4). ⋯ The afterdrop and rewarming rate were 0.38 degrees C and 0.8 degrees C/h, respectively. Method 4 had the lowest rewarming rate (0.2 degrees C/h), and an afterdrop (0.14 degrees C) which was not significantly lower than that of Method 1 or 2. Therefore, Method 1 is recommended for rewarming mild hypothermic subjects because of its high rewarming rate and small afterdrop.